The short answer is that appliances of all sizes need to be tested as their condition may deteriorate over time making them potentially dangerous to use.
Some of this deterioration can be seen – cut or damaged flexes, overheated plugs and so on, but some cannot be detected without the use of specialist equipment.
The legislation of specific relevance to electrical maintenance is the Health & Safety at Work Act 1974, the Management of Health & Safety at Work Regulations 1999, the Electricity at Work Regulations 1989, the Workplace (Health, Safety and Welfare) Regulations 1992 and the Provision and Use of Work Equipment Regulations 1998 provides a longer answer.
The Health & Safety at Work Act 1974 puts the duty of care upon both the employer and the employee to ensure the safety of all persons using the work premises. This includes the self employed.
If the worst should happen and an employee or other person is injured as a result of unsafe equipment the penalties for the owner can be very severe.
In addition, those working on other people’s premises such as DJs, musicians and performers may be required to demonstrate that their equipment is safe before they are allowed to work at a venue. We understand this and can often provide testing and PDF certificates at short notice.